1. Field
This invention concerns cam operated actuators (fill valve openers) for use with fill valves for beverage bottles, cans or the like wherein each actuator employs a camshaft provided with O-ring seals which slidably rotatably mount the camshaft in the bore of an actuator barrel for rotative motion, and wherein a braking means is provided for preventing drift of the actuation during the container filling operation, which, for example, could prevent proper filling of the container, whereby the cam can contact a cam follower on the fill valve and urge the valve between a fully opened position and a fully closed position.
2. Prior Art
A typical bottle filling machine and its fill valve structure for which the present actuator is useful, and its operation are particularly shown in U.S. Pat. No. 5,119,853, and in general, in U.S. Pat. Nos. 6,038,833; 4,086,943; 5,586,379; 5,119,853; and in British patent 810,992, the disclosures of all of which patents are hereby incorporated herein by reference in their entireties.
Referring to FIG. 3 of U.S. Pat. No. 5,119,853, with parts numbers 18, 70, 74, 79, 80, 81, 82, 84 and 86 added herein without primes for clarity to FIG. 3, a typical prior cam assembly presently also termed “actuator” 86 is shown constructed such that it can be placed above each fill valve structure of, e.g., 79 or in other existing beverage fill machines with its cam fork 72′ on the inner end portion 84 of camshaft 75′ aligned with a cam follower shoulder pair (structure) 70, 74 on the fill valve 79. The cam fork 72′ of the actuator is intended to open the fill valve structure of the filling head 81 it is associated with when the camshaft 75′ is rotated in one direction to allow the proper amount of liquid to enter the can or bottle and then to close the fill valve when the camshaft is rotated in the opposite direction.
Further to said FIG. 3, such an assembly, heretofore, would utilize a braking means such as a coiled compression spring shown as item 80 of said patent, typically used with a brake pad 82 in order to prevent the actuator camshaft from drifting toward a more closed position. These prior braking means can only afford, at best, an approximate and variable frictional braking force which, even with the most attentive assembly procedure, often and unpredictably result in sticking, stopping, drifting or other jagged rotational motion of the actuator camshaft.